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EN 1.6781 (G17NiCrMo13-6) Cast Steel

EN 1.6781 steel is an alloy steel formulated for casting. Cited properties are appropriate for the quenched and tempered condition. 1.6781 is the EN numeric designation for this material. G17NiCrMo13-6 is the EN chemical designation.

It has a fairly high base cost among cast alloy steels. In addition, it has a moderately high electrical conductivity and a moderately low ductility.

The graph bars on the material properties cards below compare EN 1.6781 steel to: cast alloy steels (top), all iron alloys (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.

Mechanical Properties

Brinell Hardness

250

Elastic (Young's, Tensile) Modulus

190 GPa 27 x 106 psi

Elongation at Break

17 %

Fatigue Strength

450 MPa 65 x 103 psi

Poisson's Ratio

0.29

Shear Modulus

73 GPa 11 x 106 psi

Tensile Strength: Ultimate (UTS)

830 MPa 120 x 103 psi

Tensile Strength: Yield (Proof)

680 MPa 98 x 103 psi

Thermal Properties

Latent Heat of Fusion

260 J/g

Maximum Temperature: Mechanical

450 °C 840 °F

Melting Completion (Liquidus)

1460 °C 2660 °F

Melting Onset (Solidus)

1420 °C 2590 °F

Specific Heat Capacity

470 J/kg-K 0.11 BTU/lb-°F

Thermal Conductivity

44 W/m-K 26 BTU/h-ft-°F

Thermal Expansion

13 µm/m-K

Electrical Properties

Electrical Conductivity: Equal Volume

7.9 % IACS

Electrical Conductivity: Equal Weight (Specific)

9.1 % IACS

Otherwise Unclassified Properties

Base Metal Price

5.0 % relative

Density

7.9 g/cm3 490 lb/ft3

Embodied Carbon

1.9 kg CO2/kg material

Embodied Energy

25 MJ/kg 11 x 103 BTU/lb

Embodied Water

60 L/kg 7.2 gal/lb

Common Calculations

PREN (Pitting Resistance)

3.3

Resilience: Ultimate (Unit Rupture Work)

130 MJ/m3

Resilience: Unit (Modulus of Resilience)

1220 kJ/m3

Stiffness to Weight: Axial

13 points

Stiffness to Weight: Bending

24 points

Strength to Weight: Axial

29 points

Strength to Weight: Bending

25 points

Thermal Diffusivity

12 mm2/s

Thermal Shock Resistance

24 points

Alloy Composition

Among cast alloy steels, the composition of EN 1.6781 steel is notable for containing comparatively high amounts of nickel (Ni) and chromium (Cr). Nickel is used to improve mechanical properties, and to make the alloy easier to heat treat. Chromium is used to improve corrosion resistance and most mechanical properties (particularly at higher temperatures).

Iron (Fe) 92.6 to 94.6
Nickel (Ni) 3.0 to 3.5
Chromium (Cr) 1.3 to 1.8
Manganese (Mn) 0.55 to 0.8
Molybdenum (Mo) 0.45 to 0.6
Silicon (Si) 0 to 0.5
Carbon (C) 0.15 to 0.19
Phosphorus (P) 0 to 0.015
Sulfur (S) 0 to 0.015

All values are % weight. Ranges represent what is permitted under applicable standards.

Followup Questions

Similar Alloys

Further Reading

ISO 4991: Steel castings for pressure purposes

EN 10293: Steel castings - Steel castings for general engineering uses

ASM Specialty Handbook: Carbon and Alloy Steels, J. R. Davis (editor), 1996

Manufacture and Uses of Alloy Steels, Henry D. Hibbard, 2005

Ferrous Materials: Steel and Cast Iron, Hans Berns and Werner Theisen, 2008

Steels: Processing, Structure, and Performance, 2nd ed., George Krauss, 2015